The objective of this proposal is to continue development of a pulsed Doppler ultrasound system and to determine its potential usefulness in evaluating specific hemo-dynamic abnormalities in cardiovascular patients. The same basic pulsed Doppler system will be applied to measuring arterial velocity profiles both transcutaneously and invasively. Velocity profiles obtained by the transcutaneous techniques will be used to construct longitudinal and cross-sectional images of peripheral arteries and the central aorta. It will also be used to determine aorta to coronary artery saphenous vein bypass patency. The invasive technique will be used to measure velocity profiles in the proximal coronary arteries at the time of routine Sones coronary arteriography. Velocity measurements obtained with a modified Sones catheter and arterial dimensions obtained by angiography will be combined to measure phasic flow thru the proximal right and left coronary arteries.